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hey anyone done this? an engine builder said i could put the 1.7 rocker arm on the intake and run it .600/.600?? Is this a common practice? never heard of something like this.
 

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Yes it is done quite a bit

It can help a bit to optimize your combination. I've heard of quite a few people who've done it. Just make sure you'll have enough piston to valve clearance.
 

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This would benifit what far as performance? Also, how if you know would that work with stock gt 40 irons?
 

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1.8,1.7,1.6 rockers and 1.5 rockers are available to increase/reduce lift.It will add/subtract 1-3 * of .050 duration.(using the theory of the valve reaching .050 faster/slower.

My combo has CNC'd E7's www.PowerHeads.com.My set of heads have been great.(made 256 rwhp with an AOD,untuned)
and have over 5000 miles n them.

flow @....100" .200" .300" .350" .400" .450"
.500"
intake.....63.5 124.0 189.5 202.9 213.0 216.5 217.0
exhaust..62.5 109.0 150.5 162.0 169.3 172.4 174.0

FWIW...These flow numbers are right off their website.;)
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Using the TFS #1 cam that I am running

adv 275*,221* @ .050 with .312 lift at the cam,.499 lift with 1.6 rockers
adv 279*, 225* @.050 with .319 lift at the cam,.510 lift with 1.6
rockers

Now in my combo a move to 1.7 rockers on the intake would give me .530 lift on the intake and increase 'effective' .050 duration by adding the theoretical 1-3* would make the intake side act like a 223* at .050 duration.

It can help get more hp from an exhuast biased set of heads like mine.With out stepping to a full blown custom cam.A custom cam would be cheaper than buying 2 sets of rockers
 

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So what about my iron gt 40's, would it help my exhaust with 1.7 on intake? I have my old set of 1.7 and also running a tfs stage 1 cam.
 

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The only deal with increasing the intake lift is piston to valve claerance.

If the 1.7's will clear on the intake,run'em.Don't expext 50 hp from this,you MAY get 10hp.The unported GT40 head is not as biased on the exhaust side as my worked E7's.Intake is about the same.The bias is the intake to exhaust flow,70-75% is a good number.Mine are in the 80%+ range and MAY respond to this .

I would spring for a custom ground cam (~$300),rather than play with $400 worth of rockers.BUT,if you have both ratios,by all means try it!:cool:
 

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Yeah, I have both sets already so I will not be spending extra. So you saying run 1.7 intake and 1.6 exhaust might net me 10 hps? I will give it a try the mix and the matched rockers.
 
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